From b1b00a5b8a6cf32e3973507decf1216709b55072 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Fri, 12 Dec 2014 16:56:56 -0800 Subject: [PATCH] zsmalloc: fix zs_init cpu notifier error handling Mahendran Ganesh reported that zpool-enabled zsmalloc should not call zpool_unregister_driver() from zs_init() if cpu notifier registration has failed, because error handling is performed before we register the driver via zpool_register_driver() call. Factor out cpu notifier registration and unregistration code and fix zs_init() error handling. link: http://lkml.iu.edu//hypermail/linux/kernel/1411.1/04156.html [akpm@linux-foundation.org: squash bogus gcc warning] [akpm@linux-foundation.org: use __init and __exit] Signed-off-by: Sergey Senozhatsky Reported-by: Mahendran Ganesh Cc: Minchan Kim Cc: Nitin Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/zsmalloc.c | 39 ++++++++++++++++++++++++--------------- 1 file changed, 24 insertions(+), 15 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index b3b57ef85830..5481c677e465 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -881,14 +881,10 @@ static struct notifier_block zs_cpu_nb = { .notifier_call = zs_cpu_notifier }; -static void zs_exit(void) +static void zs_unregister_cpu_notifier(void) { int cpu; -#ifdef CONFIG_ZPOOL - zpool_unregister_driver(&zs_zpool_driver); -#endif - cpu_notifier_register_begin(); for_each_online_cpu(cpu) @@ -898,31 +894,44 @@ static void zs_exit(void) cpu_notifier_register_done(); } -static int zs_init(void) +static int zs_register_cpu_notifier(void) { - int cpu, ret; + int cpu, uninitialized_var(ret); cpu_notifier_register_begin(); __register_cpu_notifier(&zs_cpu_nb); for_each_online_cpu(cpu) { ret = zs_cpu_notifier(NULL, CPU_UP_PREPARE, (void *)(long)cpu); - if (notifier_to_errno(ret)) { - cpu_notifier_register_done(); - goto fail; - } + if (notifier_to_errno(ret)) + break; } cpu_notifier_register_done(); + return notifier_to_errno(ret); +} +static void __exit zs_exit(void) +{ #ifdef CONFIG_ZPOOL - zpool_register_driver(&zs_zpool_driver); + zpool_unregister_driver(&zs_zpool_driver); #endif + zs_unregister_cpu_notifier(); +} + +static int __init zs_init(void) +{ + int ret = zs_register_cpu_notifier(); + + if (ret) { + zs_unregister_cpu_notifier(); + return ret; + } +#ifdef CONFIG_ZPOOL + zpool_register_driver(&zs_zpool_driver); +#endif return 0; -fail: - zs_exit(); - return notifier_to_errno(ret); } static unsigned int get_maxobj_per_zspage(int size, int pages_per_zspage) -- 2.20.1